Problem: A rectangle is $3$ feet long. The rectangle is also $7$ feet wide. What is its perimeter?
$3\text{ ft}$ $7\text{ ft}$ The perimeter is the total length of all the sides of the shape added together. Add up the lengths of the sides: $ \text{perimeter} = {7} + {3} + {7} + {3} $ $ \text{perimeter} = 20\text{ ft} $